Speedometer.



L. A. GRBBNLBAF.

BPEEDOMETER.

APPLICATION nun JUNE 9, 1910.

Patented Dec. 5, 1911 1: ing: like parts.

LOUIS A. GREENLEAF, OF 'DORGHESTER, MASSACHUSETTS.

SPEEDOMETER.

Specification of Letters Patent.

Pate ted Dec. 5. 1911.

Application filed June 9, 1910. Serial No. 565,034.-

To all whom it may concern:

Be. it known that 1, Louis A. GREENLEAF, a citizen of the United States, residing at Dorchestcr, in the county of Suffolk and State of Massachusetts, have invented an lm n'oveuient in Speedomcteis, of whichthe following description, in connection with the accompanying drawings, is a specifica- (ion, like letters on the drawings represent- My invention is a speedometer for automobiles, etc, having for its objectthe pro- \lSlOll of means not liable to need attention either for lubrication, adjustment or repair.

'lsaid air current.

5: In carrying out'my invention I rovide means responsive to the driving mec ianism of the vehicle to generate in the speedometer a current of air, and means connected with the speed hand or indicator responsive to By this sim le means I chuunate the usual train of mec ianism con- 'nected to the indicator, and practically eliminate the usualfrictional problem at the in- A dicator end of the apparatus, and thereby jeli1ninate the error and uncertaintydue' to said friction and to the bearings, gears, and other mechanism heretofore necessary in the usual apparatus. Also I have found that the errors commonly due to the centrifugal force resulting in the usual geared -0r a ;netic instrumentare minimized and practically eliminated by employing) the pneumatic connections mentioned etwcen the prime mover and the indicator, as the light,

3 5 indicator and its delicate support respond mini: n lag afijfpal'advantage is an: because of ain't jected.

,'ltll extreme accuracy, both as to time and distance, to the free air current applied di rectly thereto. In response to theair 'current, the indicator moves instantly, there be either at the beginning or at the eildof said "movement, and the indicating istance traversed by the indicator is ex- .actlv in'proportion to the prcssure or ye.- ilcicity of Saidnir current. Anotherlprinci this air c ur-' ren aet iation of 'theiudicato'r, whereby the gtt'tiif. is practically disconnected ,mec rann cal ly from its actuator,the'acculaeyo in t i'uu'entjs not affected b'y olts'"al' d. ars lihvchiclc. i

r n e :1 Chief object at my invention In ,ljepn'toproduce an instrument whose accu ,i a' =y v9ula;na be afi'ected by the .ifrequ cali;- jtiltsand jars to'vvhioh automobiles are sulf against' ik hic the invention comprises further .features of advantnge relating more speciallv to details, such as the provision of a trip indi' cater ring, means whereby the instrument when closed cannot readily be opened'by the user, the closing means being concealed, etc" all of which will be explained in connection with the more complete-detailed description of the apparatus hereinafter contained. taken with reference to the accompanying drawings, in which I have shown a preferred embodiment of my invention.

In the drawings, Figure 1 is a top plan view thereof; Fig. 2 is an approximately central vertical sectional view, parts being in elevation and parts being omitted; Fig: 3 is a fragmentary horizontal sectional view on the line 3, Fig. 2; Fig. 4 is a transverse sectional view on the line 4-4, Fig. 3'; and Fig. 5 is a'view in top plan of a detail of the indicator meqhanism.

As'herein shown, the prime mover consists of a fluted spindle or aspindle pinion 1 meshing with a beveled driving gear 2 fast on a shaft 3 which is jourualed in the main frame or base plate 4 of the instrument and projects at its outer end through an otherwise s'olid 5 threaded at t: for a flexible shaft connection (not shown) to contain a usual flexible shaft driven from the wheel of the vehicle, the outer end of the shaft 3 being herein shown as squared 211-7 to receive said flexible shaft in well khownnrauuer. On the upper end S of the driving spindle is fixed a fan 9 or equivalent wind'producer, to generate a current of air directed on an air responsive device, herein shown as a similar fan 10, which except for the air connection between the two is otlierwise unconnected with the prime moving parts contained in the lower portion 'of the speedometer-Q This fan 10 is pro- 'vided with a short shaft 11 journaled in a bearing 12 provided in a'supporting diaphragni'ifipr otherwise braced'which provides nnlouter cha'mber 14 and a lower chamr lier"1 5.- ISeouredto the outer end of the shaft: 1121? aspeed hand or pointer 16 or v im 'a', a1; 1hr preferred "means, for indicatfing'ito the bbserver'the speed of travel, said 'speled "hat tl being herein shown a's co'liperatingnitlt-it: speed scale 17;.thc' zero being 'showrias bii inni'n 'i1t'tl1e'1imiting post 18 in' u'scl' "AnV suitablo means may be provi'deil for Tolding'the speed hand in normal positionsaga'inst the movement of the fan land 16 is held "when not 10, said means as herein shown consisting of an eccentric lever or plate 19 fast on the shaft 11 just above the hearing 19, to which plate a liexible cord or wire 20 is secured at .31 provided with a spring 22 supported in a post 23 and adjusta le b v a nut 2i. I. tind it. of advantage to provide an annular housing or current director 2.": surrounding the two fans and open at its opposite ends for the passage thercthrough and laterally therefrom of the air current, said annulus or director 25 lxing supported on the frame posts 26 of the instrument which extend rigidly upward from the base 4. .Uso mounted on said base is a stub shaft 27 provided with a worm-wheel 2S nieshing with a .worm 2!) fast on the under side of the gear 2 for driving a train of gears 30, 31, 32, 33, 34-. The latter is provided with an eccentric 35 which operates a pawl in engagen'ient with the ratchet teeth 37 of an indicator ring 38 whose figures 3.) indicate the distance of'any given trip, said ring being turned around to zero at any time desired by a gear 40, the outer end of whose post 41 terminates in a thumb nut 42 for this purpose. A usual odometer is also preferably provided, to be driven by the same train of gears, the same however not constitntin a feature of my present invention. The foregoing apparatus is inclosed bv a shell 43 having a glass outer end 44 and at its inner lower rim provided with a groove 45 to receive two lugs 46 projecting upward from the base 4 as shown in Fig. 4. The shell 43 is slightly larger than the dial )late or diaphragm 13, so that when it is placed over the mechanism it is moved to one side slightly so as to permit the overhanging lugs 44' to enter the groove 45 at that side of the instrument, and-is then moved laterally so as to bring the lugs into interlocking, engagement with the shell, which when in this position fits snugly against a supporting wall 47 of a holding bracket 48, where it is secured by a screw 49. The bracket 48 is providedatits rear side with a recess 50 and when the screw 49 has been turned home I cover it with a layer of putty or cement 51 and then paint or enamel-the adjacent surface with a. coating 52, whereby the screw 49 is entirely concealed. The general object of the housing construction and securing means which I have just explained is to prevent, the ordinary user from getting at the interior mechanism of the speedometer, which is also thus practically hermetically -aled. l have found thatthe average user of such devices on automobiles has a strong inclination to investigate, adjust and other-- wise tamper with his speedometer, and as the instrumcntis necessarily delicate, and, if reliable, -must be let alone, I have pro vidcd the'above described construction for 'mcuring this result. I have provided a mechanism in which the speed indiealor portion thereof is, a previously stat d. not n|cch.-uueall v coi mected with the moving portion thcreol but in wlueh the powci transmitting means consists of a controlled current of air, and accordingly it is of considerable. practical value to have in con ncclion therewith a construction \rherehv this air control cannot be extcrnallv iiilluenccd or tampered with. i

The operation of m v invention ha alreadv een explained in conn ction with its constru lion. the hat'l it and ll\ gear 2 rolate the pinion l and fan 9, a current of air is produced. varying in vclocit with the speed of the fan. and this current of air operate on the fan It) to rotate the latter and therein actuate the indicator. herein shown as the distance hand lt'. 'l'hc dia- -phra :m 13 keeps the blast of air from in- 'drical 'member.

lluencing the indicator in any way. and the eccentric lever 19 and spring maintain a uniform movement of the. latter under the varying vclocit of the air current,

It will be obvious to those skilled in the art that various regulating means may be employed, and also that the operation 01 the device may be materially regulated and varied by varyingthe relative proportions and crms'trnctions of the two fans. Also it is to be noted that in device ma be operatcd in either direction, the main diflerence being that the fan 10 is operated in one direction by a suction current and in the other direction by an impingg'in l current. the direction of numbering the scale and the direction oi pull of the regulating spring corresponding. of course, to the direction of rota tion of the fan mechanism.

As already implied, it will be understood that my invention may be embodied in a wide range of mechanical constructions. certain features of my invention. as will be more apparent from the claims, being broadly new.

Having described my clairu as new and desire .ters Patent. is:

l. A speedometer comprising an inclosure, a continuous hollow cylindrical member invention, what I to secure by Let- .therein, means for holding said member in a spa ed apart relation to the walls thereof to cave an'opcn annular space, air current producing means wholly within said cylina drawing connection thereto, and means also wholly within said cylin- 'drical member responsive to an air current and having connected thereto a device to in dicate the force thereof, said parts being constructed and arranged to produce a closed circulation of air in'one direction through the interior of said cylindrical member. returning in the opposite direction through said unobstructed open annular space.

2. A speedometer, comprising a tight inclosure, a continuous hollow cylindrical member, means for holding said member in spaced apart relation to the walls thereof to form an unobstructed annular space, air current. producing means mounted wholly within said member, a driving connection thereto, means also wholly within said member responsive to an air current and a dcvice'connected to be operated thereby to indicate the force thcrt-ot, said parts be ing constructed to maintain a closed circw lation of air in one direction through said hollow cylindrical member and in the other direction through the unobstructed annular space between the same and.thc wall of said inclosure.

3. A speedometer, comprising an inclosing cylinder, a hollow cylindrical section having a mounting in said cylinder in spaced apart. relation to the cylindrical wall thenof, air current producing means mounted wholly within said section and having a driving connection extending therefrom, and means also wholly within said section responsive to an air current and having connected thereto a device to indicate the force thereof, said parts being fitted to the interior of said section and constructed to cause a elm-ed circulation of air in one direction through said cylindrical section and to permit its free return withoutinterference through the annular space between said cylindrical section and said inclosing cylinder.

4. A speedometer, comprising a tight inclosure, a continuous and hollow cylindrical member, means for holdin said member in spaced-apart relation to the Walls of saidinclosure to leave an unobstructed annular space therebetween, a fan fitted to rotate wholly within said member, having a mounting coaxial therewith and a driving connection, a second fan mounted op osite said first fan and fitted to rotate who ly within said member, and means connected to said second 'fan for 'ndicating the force of an air ,cur-

rent generated by said first fan, said parts being constructed tomaintain a closed circulation of air in one direction through said hollow cylindrical member and in the other direction through the unobstructed annular space between the same and the wall of said inclosure.

5. speedometer, comprising a base, indicating mechanism, an inclosure for the latter in'imovablv secured to said base when in operative position, the securing means being externally inaccessible, a bracket for fastening the apparatus to the vehicle. means for rcmovably securing the said apparatus to the bracket, and means for concealing the securing means within the bracket.

(3. A speedometer, comprising a base provided at its front side adjacent one edge with overhanging radially projecting lugs, indicating mechanism, an inclosure for the latter having adjacent its lower edge an inwardly opening groove for receiving said lugs, a bracket adjacent the opposite edge of said base, and threaded means operable from the rear of said bracket for securing 1,:

said inclosure in place on said base and against the bracket.

7. A speedometer, comprising a basc,,indieating mechanism, an inclosure for the latter immovablv secured to said base when in operative position, the externally inaccessible, a bracket for fastening the apparatus to the vehicle, said bracket containing a cavity opening toward the rear and extending forwardly into the bracket, and a screw-hole adjacentsaid inclosure, a screw fitting said hole and having threaded engagement with said inclosure, and a protecting coating for concealing said screw and covering the adjacent surface of the bracket within said cavity.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

GEO. H. MAXWELL, M. J. ramme.

securing means being It is hereby certified that in Letters Patent; No. 1,011,051 granted December 5,

1911,1 p0n the application of Louis A. Greenleaf, of Dorchester, Massachusetts, for sin improvement in S -ultimatum, an error appears in the printed spccifiiuitipn requiring correction as fullrnw: Page 2, line 120, for the Word drawing rend (hiring; and that the said Letters Patent siiuuld be read with this correction therein that the same umy conform to th" record of the cam in tht l'atent Office.

' Signiad and sealed this 28% day of licomnhr. 13 19.

C. C. BILLINGS, Acting Commissimier of Patents.

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